Vitamin C : effects of exercise and requirements with training

Ascorbic acid or vitamin C is involved in a number of biochemical pathways that are important to exercise metabolism and the health of exercising individuals. This review reports the results of studies investigating the requirement for vitamin C with exercise on the basis of dietary vitamin C intakes, the response to supplementation and alterations in plasma, serum, and leukocyte ascorbic acid concentration following both acute exercise and regular training. The possible physiological significance of changes in ascorbic acid with exercise is also addressed. Exercise generally causes a transient increase in circulating ascorbic acid in the hours following exercise, but a decline below pre-exercise levels occurs in the days after prolonged exercise. These changes could be associated with increased exercise-induced oxidative stress. On the basis of alterations in the concentration of ascorbic acid within the blood, it remains unclear if regular exercise increases the metabolism of vitamin C. However, the similar dietary intakes and responses to supplementation between athletes and nonathletes suggest that regular exercise does not increase the requirement for vitamin C in athletes. Two novel hypotheses are put forward to explain recent findings of attenuated levels of cortisol postexercise following supplementation with high doses of vitamin C.

Towards a capabilities database to inform inclusive design : Experimental investigation of effective survey-based predictors of human-product interaction

A key issue in the field of inclusive design is the ability to provide designers with an understanding of people's range of capabilities. Since it is not feasible to assess product interactions with a large sample, this paper assesses a range of proxy measures of design-relevant capabilities. It describes a study that was conducted to identify which measures provide the best prediction of people's abilities to use a range of products. A detailed investigation with 100 respondents aged 50-80 years was undertaken to examine how they manage typical household products. Predictor variables included self-report and performance measures across a variety of capabilities (vision, hearing, dexterity and cognitive function), component activities used in product interactions (e.g. using a remote control, touch screen) and psychological characteristics (e.g. self-efficacy, confidence with using electronic devices). Results showed, as expected, a higher prevalence of visual, hearing, dexterity, cognitive and product interaction difficulties in the 65-80 age group. Regression analyses showed that, in addition to age, performance measures of vision (acuity, contrast sensitivity) and hearing (hearing threshold) and self-report and performance measures of component activities are strong predictors of successful product interactions. These findings will guide the choice of measures to be used in a subsequent national survey of design-relevant capabilities, which will lead to the creation of a capability database. This will be converted into a tool for designers to understand the implications of their design decisions, so that they can design products in a more inclusive way.

A finite element model of seat cushion indentation with a soft tissue human occupant model

Effective digital human model (DHM) simulation of automotive driver packaging ergonomics, safety and comfort depends on accurate modelling of occupant posture, which is strongly related to the mechanical interaction between human body soft tissue and flexible seat components. This paper presents a finite-element study simulating the deflection of seat cushion foam and supportive seat structures, as well as human buttock and thigh soft tissue when seated. The three-dimensional data used for modelling thigh and buttock geometry were taken on one 95th percentile male subject, representing the bivariate percentiles of the combined hip breadth (seated) and buttock-to-knee length distributions of a selected Australian and US population. A thigh-buttock surface shell based on this data was generated for the analytic model. A 6mm neoprene layer was offset from the shell to account for the compression of body tissue expected through sitting in a seat. The thigh-buttock model is therefore made of two layers, covering thin to moderate thigh and buttock proportions, but not more fleshy sizes. To replicate the effects of skin and fat, the neoprene rubber layer was modelled as a hyperelastic material with viscoelastic behaviour in a Neo-Hookean material model. Finite element (FE) analysis was performed in ANSYS V13 WB (Canonsburg, USA). It is hypothesized that the presented FE simulation delivers a valid result, compared to a standard SAE physical test and the real phenomenon of human-seat indentation. The analytical model is based on the CAD assembly of a Ford Territory seat. The optimized seat frame, suspension and foam pad CAD data were transformed and meshed into FE models and indented by the two layer, soft surface human FE model. Converging results with the least computational effort were achieved for a bonded connection between cushion and seat base as well as cushion and suspension, no separation between neoprene and indenter shell and a frictional connection between cushion pad and neoprene. The result is compared to a previous simulation of an indentation with a hard shell human finite-element model of equal geometry, and to the physical indentation result, which is approached with very high fidelity. We conclude that (a) SAE composite buttock form indentation of a suspended seat cushion can be validly simulated in a FE model of merely similar geometry, but using a two-layer hard/soft structure. (b) Human-seat indentation of a suspended seat cushion can be validly simulated with a simplified human buttock-thigh model for a selected anthropomorphism.

Is CEO human capital related to firm performance?

The global economy experienced continuous growth from 2002 to 2007 until the U.S. subprime mortgage crisis caused instability in worldwide stock markets. Simultaneously, global CEO turnover continued to fall to 13.8 percent in 2007. In contrast, the CEO turnover rate in Australia increased to 18 percent in 2007. The purpose of this paper is to determine under what conditions a change in a CEO is associated with firm performance. Succinctly, does the firm’s decision to replace the CEO depend on the CEO’s human capital or firm performance? The empirical study of Australian listed firms (2005 – 2008) shows that firm performance is not a determinant of CEO turnover, rather a CEO with less valuable human capital is more likely to be replaced. The study also finds that merely changing the CEO is not associated firm performance. Rather, there is a positive association between firm performance and the successor’s general human capital for firms that replace the CEO. Specifically, it is the internal successor’s general human capital that is an important determinant of increasing firm performance. These results are important because they imply that CEO turnover is a result of a more active market for CEOs and contributes to explaining why firms retain CEOs despite poor firm performance.

Human single-stranded DNA binding proteins are essential for maintaining genomic stability

The double-stranded conformation of cellular DNA is a central aspect of DNA stabilisation and protection. The helix preserves the genetic code against chemical and enzymatic degradation, metabolic activation, and formation of secondary structures. However, there are various instances where single-stranded DNA is exposed, such as during replication or transcription, in the synthesis of chromosome ends, and following DNA damage. In these instances, single-stranded DNA binding proteins are essential for the sequestration and processing of single-stranded DNA. In order to bind single-stranded DNA, these proteins utilise a characteristic and evolutionary conserved single-stranded DNA-binding domain, the oligonucleotide/oligosaccharide-binding (OB)-fold. In the current review we discuss a subset of these proteins involved in the direct maintenance of genomic stability, an important cellular process in the conservation of cellular viability and prevention of malignant transformation. We discuss the central roles of single-stranded DNA binding proteins from the OB-fold domain family in DNA replication, the restart of stalled replication forks, DNA damage repair, cell cycle-checkpoint activation, and telomere maintenance.

Incorporation of exogenous RGD peptide and inter-species blending as strategies for enhancing human corneal limbal epithelial cell growth on Bombyx mori silk fibroin membranes

While fibroin isolated from the cocoons of domesticated silkworm Bombyx mori supports growth of human corneal limbal epithelial (HLE) cells, the mechanism of cell attachment remains unclear. In the present study we sought to enhance the attachment of HLE cells to membranes of Bombyx mori silk fibroin (BMSF) through surface functionalization with an arginine-glycine-aspartic acid (RGD)-containing peptide. Moreover, we have examined the response of HLE cells to BMSF when blended with the fibroin produced by a wild silkworm, Antheraea pernyi, which is known to contain RGD sequences within its primary structure. A procedure to isolate A. pernyi silk fibroin (APSF) from the cocoons was established, and blends of the two fibroins were prepared at five different BMSF/APSF ratios. In another experiment, BMSF surface was modified by binding chemically the GRGDSPC peptide using a water-soluble carbodiimide. Primary HLE were grown in the absence of serum on membranes made of BMSF, APSF, and their blends, as well as on RGD-modified BMSF. There was no statistically significant enhancing effect on the cell attachment due to the RGD presence. This suggests that the adhesion through RGD ligands may have a complex mechanism, and the investigated strategies are of limited value unless the factors contributing to this mechanism become better known.

The Human Fertilisation and Embryology Act 2008 : restrictions on the creation of “saviour siblings” and the relevance of the harm principle

This paper provides an overview of the regulatory developments in the UK which impact on the use of in vitro fertilization (IVF) and embryo screening techniques for the creation of “saviour siblings.” Prior to the changes implemented under the Human Fertilisation and Embryology Act 2008, this specific use of IVF was not addressed by the legislative framework and regulated only by way of policy issued by the Human Fertilisation and Embryology Authority (HFEA). Following the implementation of the statutory reforms, a number of restrictive conditions are now imposed on the face of the legislation. This paper considers whether there is any justification for restricting access to IVF and pre-implantation tissue typing for the creation of “saviour siblings.” The analysis is undertaken by examining the normative factors that have guided the development of the UK regulatory approach prior to the 2008 legislative reforms. The approach adopted in relation to the “saviour sibling” issue is compared to more general HFEA policy, which has prioritized the notion of reproductive choice and determined that restrictions on access are only justified on the basis of harm considerations.

Preventing the selection of “deaf embryos” under the Human Fertilisation and Embryology Act 2008 : problematizing disability?

Section 14(4) of the Human Fertilisation and Embryology Act 2008 imposes – within the general licensing conditions listed in the Human Fertilisation and Embryology Act 1990 – a prohibition to prevent the selection and implantation of embryos for the purpose of creating a child who will be born with a “serious disability.” This article offers a perspective that demonstrates the problematic nature of the consultation, review, and legislative reform process surrounding s 14(4). The term “serious disability” is not defined within the legislation, but we highlight the fact that s 14(4) was passed with the case of selecting deaf children in mind. We consider some of the literature on the topic of disability and deafness, which, we think, casts some doubt on the view that deafness is a “serious disability.” The main position we advance is that the lack of serious engagement with alternative viewpoints during the legislative process was unsatisfactory. We argue that the contested nature of deafness necessitates a more robust consultation process and a clearer explanation and defence of the normative position that underpins s 14(4).

Editorial: The Human Fertilisation and Embryology Act 2008

This editorial first describes the workshop out of which the present special issue arose. The editors then identify the need for a multidisciplinary collection examining the Human Fertilisation and Embryology Act 2008 from both legal and political perspectives, including the consultation process, campaigning and parliamentary debates leading to its passage, and the concluded legislation and its effects. The editorial provides an overview of the legislative reform process, key legislative changes, and the various contributions to the special issue. Cross-cutting themes include the value of a qualitative, discourse-based approach to research in this area; the need to understand the 2008 Act in historical context; unforeseen practical implications of the legislative provisions; and silences and missed opportunities in the legislation. Finally, a postscript covers the changing landscape of hybrid embryo research since the passage of the Act, and the uncertain future of the Human Fertilisation and Embryology Authority at the time of writing.

Load bearing improves the limits of agreement for repeated in vivo measures of the speed of sound in human Achilles tendon

Axial acoustic wave propagation has been widely used in evaluating the mechanical properties of human bone in vivo. However, application of this technique to monitor soft tissues, such as tendon, has received comparatively little scientific attention. Laboratory-based research has established that axial acoustic wave transmission is not only related to the physical properties of equine tendon but is also proportional to tensile load to which it is exposed (Miles et al., 1996; Pourcelot et al., 2005). The reproducibility of the technique for in vivo measurements in human tendon, however, has not been established. The aim of this study was to evaluate the limits of agreement for repeated measures of the speed of sound (SoS) in human Achilles tendon in vivo. Methods: A custom built ultrasound device, consisting of an A-mode 1MHz emitter and two regularly spaced receivers, was used to measure the SoS in the mid-portion of the Achilles tendon in ten healthy males and ten females (mean age: 33.8 years, range 23-56 yrs; height: 1.73±0.08 m; weight: 68.4±15.3 kg). The emitter and receivers were held at fixed positions by a polyethylene frame and maintained in close contact with the skin overlying the tendon by means of elasticated straps. Repeated SoS measurements were taken with the subject prone (non-weightbearing and relaxed Achilles tendon) and during quiet bipedal and unipedal stance. In each instance, the device was detached and repositioned prior to measurement. Results: Limits of agreement for repeated SoS measures during non-weightbearing and bipedal and unipedal stance were ±53, ±28 and ±21 m/s, respectively. The average SoS in the non-weightbearing Achilles tendon was 1804±198 m/s. There was a significant increase in the average SoS during bilateral (2122±135 m/s) (P < 0.05) and unilateral (2221±79 m/s) stance (P < 0.05). Conclusions: Repeated SoS measures in human Achilles tendon were more reliable during stance than under non-weightbearing conditions. These findings are consistent with previous research in equine tendon in which lower variability in SoS was observed with increasing tensile load (Crevier-Denoix et al, 2009). Since the limits of agreement for Achilles tendon SoS are nearly 5% of the changes previously observed during walking and therapeutic heel raise exercises, acoustic wave transmission provides a promising new non-invasive method for determining tendon properties during sports and rehabilitation related activities.

Overweight and obesity alters the cumulative transverse strain in the Achilles tendon immediately following exercise

This research evaluated the effect of obesity on the acute cumulative transverse strain of the Achilles tendon in response to exercise. Twenty healthy adult males were categorized into ‘low normal-weight’ (BMI <23 kg m−2) and ‘overweight’ (BMI >27.5 kg m−2) groups based on intermediate cut-off points recommended by the World Health Organization. Longitudinal sonograms of the right Achilles tendon were acquired immediately prior and following weight-bearing ankle exercises. Achilles tendon thickness was measured 20-mm proximal to the calcaneal insertion and transverse tendon strain was calculated as the natural log of the ratio of post- to pre-exercise tendon thickness. The Achilles tendon was thicker in the overweight group both prior to (t18 = −2.91, P = 0.009) and following (t18 = −4.87, P < 0.001) exercise. The acute transverse strain response of the Achilles tendon in the overweight group (−10.7 ± 2.5%), however, was almost half that of the ‘low normal-weight’ (−19.5 ± 7.4%) group (t18 = −3.56, P = 0.004). These findings suggest that obesity is associated with structural changes in tendon that impairs intra-tendinous fluid movement in response to load and provides new insights into the link between tendon pathology and overweight and obesity.

Environment and Interaction: a study in social activation of the public realm

The natural and built environment has been shown to affect its users in both psychological and physiological forms. But can if affect the sociological aspects of human processes and actions? The activation of the public realm can be shown to reduce socially dysfunctional behaviour through the simple occupation of the space and a number of other key variables through its design. In order to explore this further we must study how public space is being used in terms of social interaction, which will lead to a set of design ideals through which the social activation of public space can be achieved. Observations of differing social contexts have been undertaken in order to solidify key ideas and design principles for the activation of public space. Three sites were selected, each containing different amounts of vegetation and opportunity for occupation. These were then analysed through a lens of levels of social interaction. In this way it can become evident how the users interact with and within their social environments Through the analysis of the chosen sites, it has become evident that levels of interaction between the users, whether for transitory or occupational purposes, rise directly with vegetation and opportunity for occupation. With this in mind it can be determined that through design, public space can allow for and create greater opportunity for social interaction.

Emptiness and fullness : Pinter, anti-architecture and politics

Classical architecture has a long history of representing the idealized proportions of the human body, derived from the Vitruvian man. This association with the idealized human form has also associated architecture as symbiotic with prevailing power structures. Meaning that architecture is always loaded with some signification, it creates a highly inscribed space. In the absence of architecture space is not necessarily without inscription, for within the void there can exist an anti-architecture. Like the black box theatre, it is both empty and full at the same time, in the absence of the architecture, the void of space and how it is occupied becomes much more profound. As Dorita Hannah writes, ‘In denying a purely visual apprehension of built space, and suggesting a profound interiority, the black-box posits a new way of regarding the body in space.’ This paper analyses the work of Harold Pinter and his use of the body to create an anti-architecture to subvert oppressors and power structures. Pinter’s works are an important case study in this research due to their political nature. His works are also heavily tied to territory, which bound the works in a dependent relationship with a simulated ‘place’. In the citation accompanying the playwright’s Nobel Laureate it states, '...in his plays [he] uncovers the precipice under everyday prattle and forces entry into oppression's closed rooms.' In Pinter’s work oppression manifests itself in the representation of a room, the architecture, which is the cause of a power struggle when objectified and defeated when subjectified. The following work examines how Pinter uses the body to subjectify and represent architecture as authority in his earlier works, which relied on detailed mimetic sets of domestic rooms, and then in his later political works, that were freed of representational scenography. This paper will also look at the adaption of Pinter’s work by the Belarus Free Theatre in their 2008 production of ‘Being Harold Pinter.’ The work of Pinter and the Belarus Free Theatre are concerned with authoritarian political structures. That is, political structures that works against ideas of individualism, ascribing to a mass-produced body as an artifact of dictatorship and conservatism. The focus on the body in space on an empty stage draws attention to the individual – the body amongst scenography can become merely another prop, lost in the borders and boundaries the scenery dictates. Through an analysis of selected works by Harold Pinter and their interpretations, this paper examines this paradox of emptiness and fullness through the body as anti-architecture in performance.

Stockholm Syndrome : architecture, politics and the human body

The exchange between the body and architecture walks a fine line between violence and pleasure. It is through the body that the subject engages with the architectural act, not via thought or reason, but through action. The materiality of architecture is the often the catalyst for some intense association; the wall that defines gender or class, the double bolted door that incarcerates, the enclosed privacy of the bedroom to the love affair. Architecture is the physical manifestation of Lefebvre’s inscribed space. It enacts the social and political systems through bodily occupation. Architecture, when tested by the occupation of bodies, anchors ideology in both space and time. The architect’s script can be powerful when rehearsed honestly to the building’s intentions and just as beautiful when rebuked by the act of protest or unfaithful occupation. This research examines this fine line of violence and pleasure in architecture through performance, in the work of Bryony Lavin’s play Stockholm and Revolving Door by Allora & Calzadilla as part of the recent Kaldor Public Art Projects exhibition 13 Rooms in Sydney. The research is underpinned by the work of Architect and theorist, Bernard Tschumi in his two essays, Violence of Architecture and The Pleasure of Architecture. Studying architecture through the lens of performance shifts the focus of examination from pure thought to the body; because architecture is occupied through the body and not the mind.